package com.server.utils;

import java.io.UnsupportedEncodingException;
import java.security.AlgorithmParameters;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.Security;
import java.security.spec.InvalidParameterSpecException;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

import org.apache.log4j.Logger;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.codehaus.xfire.util.Base64;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;

/**
 * 解析微信登录后的用户信息
 * @author Andrew
 * @date 2017-12-05
 */
public class WXAppUserInfo {

	private static Logger logger = Logger.getLogger(WXAppUserInfo.class);
	
	public static JSONObject getSessionKeyOrOpenId(String code) {
		//微信端登录code值  
        String wxCode = code; 
        // 请求地址
        String requestUrl = Constants.WEIXIN_URL;
        Map<String,String> requestUrlParam = new HashMap<String,String>();
        requestUrlParam.put("appid", Constants.APP_ID);
        requestUrlParam.put("secret", Constants.APP_SECRET);
        requestUrlParam.put("js_code", wxCode);
        requestUrlParam.put("grant_type", "authorization_code"); // 默认参数
        //发送post请求读取调用微信 https://api.weixin.qq.com/sns/jscode2session 接口获取openid用户唯一标识  
        JSONObject jsonObject = JSON.parseObject(HttpUtils.sendPost(requestUrl, requestUrlParam));  
        return jsonObject; 
	}
	
	/**
	 * 解密用户敏感信息获取用户信息
	 * @param encryptedData 包括敏感数据在内的完整用户信息的加密数据 
	 * @param sessionKey 数据进行加密签名的密钥
	 * @param iv 加密算法的初始向量
	 * @return
	 */
	public static JSONObject getUserInfo(String encryptedData,String sessionKey,String iv) {
		// 被加密的数据  
        byte[] dataByte = Base64.decode(encryptedData);  
        // 加密秘钥  
        byte[] keyByte = Base64.decode(sessionKey);  
        // 偏移量  
        byte[] ivByte = Base64.decode(iv); 
        
        try {
        	// 如果密钥不足16位，那么就补足.  这个if 中的内容很重要  
            int base = 16;  
            if (keyByte.length % base != 0) {  
                int groups = keyByte.length / base + (keyByte.length % base != 0 ? 1 : 0);  
                byte[] temp = new byte[groups * base];  
                Arrays.fill(temp, (byte) 0);  
                System.arraycopy(keyByte, 0, temp, 0, keyByte.length);  
                keyByte = temp;  
            }  
            
         // 初始化  
            Security.addProvider(new BouncyCastleProvider());  
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding","BC");  
            SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");  
            AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");  
            parameters.init(new IvParameterSpec(ivByte));  
            cipher.init(Cipher.DECRYPT_MODE, spec, parameters);// 初始化  
            byte[] resultByte = cipher.doFinal(dataByte);  
            if (null != resultByte && resultByte.length > 0) {  
                String result = new String(resultByte, "UTF-8");  
                return JSON.parseObject(result);  
            } 
		} catch (NoSuchAlgorithmException e) {  
			logger.error(e.getMessage(), e);  
        } catch (NoSuchPaddingException e) {  
            logger.error(e.getMessage(), e);  
        } catch (InvalidParameterSpecException e) {  
        	logger.error(e.getMessage(), e);  
        } catch (IllegalBlockSizeException e) {  
        	logger.error(e.getMessage(), e);  
        } catch (BadPaddingException e) {  
        	logger.error(e.getMessage(), e);  
        } catch (UnsupportedEncodingException e) {  
        	logger.error(e.getMessage(), e);  
        } catch (InvalidKeyException e) {  
        	logger.error(e.getMessage(), e);  
        } catch (InvalidAlgorithmParameterException e) {  
        	logger.error(e.getMessage(), e);  
        } catch (NoSuchProviderException e) {  
        	logger.error(e.getMessage(), e);  
        }  
        return null;  
	}
}
